IEEE Spectrum: Holiday Gifts

IEEE SPECTRUM EDITOR'S PICK

20Q

Price: US $14

PHOTO: RANDI SILBERMAN

The least expensive and smallest item in this year's roundup of holiday gifts, the 20Q from Radica Games Ltd., in Hong Kong, is easy to overlook, but it features some of the cleverest technology around. Built into a handheld translucent, flattened plastic sphere, the 20Q has a glowing red text display, a few control buttons, and a surprisingly knowledgeable artificial intelligence (AI) system. The basis of the 20Q is the traditional word game known as 20 Questions, in which one player thinks of an object and the other players ask a series of "yes" or "no" questions until they guess the object or run out of their allotted number of questions.

Surprisingly, the 20Q adopts the role of the questioner, a task that requires a great amount of common sense in dealing with a wide range of everyday objects. This is something that even high-powered AI systems are notoriously bad at, let alone the kind of AI that can be squeezed into the cheap embedded microcontroller at the heart of the 20Q.

Yet the 20Q is so good at guessing, it's almost scary. Objects like "dragon," "hard disk," and "mushroom" proved to be no challenge, as the 20Q asked me seemingly random questions ranging from the routine—"Is it bigger than a microwave oven?"—to the offbeat—"Do you know any songs about it?"—before coming up with the right answer. But the 20Q is not infallible: "cellphone" stumped it completely, for example, and it took 25 questions instead of 20 to guess "war."

The soul of the 20Q is a cut-down version of a neural network that the inventor, Robin Burgener, has been developing for almost two decades. Starting with one question—"Animal, vegetable, or mineral?"—and one object—"cat"—he trained the neural network by getting friends and family to play with it, slowly adding questions and objects as time went on.

Eventually, he hooked his system up to the Internet and began pitting the system against all comers. (You can play against the complete neural network at http://20Q.com.) To bring his AI down to handheld size, Burgener analyzed his network and extracted hundreds of the most commonly thought-of objects and most perspicacious questions.

The result is surprisingly robust. Even a few incorrectly answered questions won't necessarily throw the 20Q off the scent. It's also quite addictive and fun to play, with the 20Q throwing in taunts as it tries to divine your thoughts. For marrying cunning technology with great entertainment value at a low price, the 20Q is this year's Editor's Pick

Holokit

Price: US $109

http://www.integraf.com

As digital photography relentlessly displaces traditional film photography, it's nice to know that there's one futuristic trick that today's snazzy all-electronic cameras can't do: holography.

Capturing truly three-dimensional images of objects still requires using photographic plates made of glass or plastic that must be developed using darkroom procedures familiar to generations of photographers. What's new is the advent of cheap solid-state lasers, which allow you to make holograms without the expensive gas lasers required in earlier years.

IMAGE: INTEgraf

Do-It Yourself-3-D: The Holokit lets you make your own holograms.

Holokit, from Integraf LLC, Kirkland, Wash., puts it all together in a box. Unlike the other kits reviewed this month, Holokits are not for young children. For one thing, the kit requires you to make up your own developing solutions. Integraf has made this a very straightforward process by giving you exactly the right amount of chemicals to be dissolved in distilled water, but some of the compounds are toxic and require careful handling. Once mixed, though, the solutions are safer than many household cleaning supplies, and older children and teens should be able to use the kit with adult supervision.

For another thing, making and developing holograms requires a modicum of self-discipline. The tiniest vibration while the object and photographic plate are being exposed to laser light can ruin a hologram, so the 10-second or so exposures must be taken in absolute silence and with as little movement as possible. Once the holograms are exposed, they spend between 30 seconds and 2 minutes in each of five developing stages (longer is better), most of which must be done in a low-light environment—Integraf recommends a room dark enough so that you can't read a newspaper's text but bright enough to read the headlines.

I tested Integraf's Student Holokit, which comes with 12 square glass plates, 63 millimeters on a side, and a red diode laser. (A cheaper kit comes with larger plastic film plates, and a more expensive kit comes with additional glass plates.) Setting up the apparatus required some household ingenuity, because the only place in my apartment dark enough to take and develop the exposures is the bathroom, which, like most New York City bathrooms, is pretty cramped. However, with some folding dinner tables deployed in the bathtub to provide an optical bench of sorts and an old pretzel tin pressed into service as a stand for the laser, I was able to start making holograms.

Not everything can be holographed. The vibration problem means that things made out of flexible or soft materials, such as cloth or paper, are likely to deform during the exposure, destroying the hologram. Metal and porcelain objects are best, and so I followed the advice in the instructions and started with coins, producing a detailed and bright hologram. Emboldened, I embarked on a hit-or-miss series of exposures of various objects—my Hot Wheels model of the Sojurner Mars Rover came out well, but what I thought was a much less ambitious image of my tiny metal souvenir of the Seattle Space Needle produced little more than a rainbow blur.

It's a thrill to hold a hologram you've made yourself and see a 3-D image emerge from the glass, and I'm sure that with a little bit more practice, I could start producing them reliably. (Integraf also sells replacement chemicals and plates for its kits.) However, I have to stop for now—my wife wants to use the bathroom.

Holiday Gifts Continued By Stephen Cass

IEEE SPECTRUM EDITOR'S PICK

Holokit

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